Articulated arm especially for a device for optically capturing objects

ABSTRACT

An articulated arm for the alignment or a capturing device for optically capturing an object to be placed on a support surface, has—as a conventional double parallelogram arm—a base part, a top part, an articulate part and two pairs of rods which connect the base part or the top part to the articulated part. The articulated arm furthermore has a shaft which is rotatably fastened to the top part and has an operative mechanical connection to one of the rods pivotably fastened to the top part. This operative connection results in a rotation of the shaft relative to the top part on pivoting of the rod.

The invention relates to an articulated arm for positioning andorienting a capturing means for optically capturing an object relativeto a support surface provided for the object, in at least one positionfor use and one transport position, according to the precharacterizingclause of claim 1.

Articulated arms have long been known in the form of doubleparallelogram arms and have proved widely useful in various devices, forexample in table lamps, in movable monitor consoles or in telephoneswivel arms. An element connected to a base via a double parallelogramarm—for example the lighting means fastened to the parallelogram arm andthe lamp base of a desk lamp—have the same orientation relative to oneanother in different positions.

German Application 38 22 008 A1 discloses a double parallelogram arm inthe form of a telephone swivel arm whose two parallelogram arms arecoupled by means of engaging gear elements. This imposes a simultaneouspivoting motion of both parallelogram arms.

U.S. Pat. No. 4,234,150 discloses such a coupled double parallelogramarm in the form of a manipulator arm. Moreover a drive motor is providedby which the double parallelogram arm pivotally mounted on the base partis driveable also by means of engaging gear elements. As bothparallelogram arms have the same length the distal end of the doubleparallelogram arm is moveable in a straight line by means of the drivemotor.

German Patent 36 38 157 furthermore discloses a reflector-like projectorwhose projection means is held by means of a double parallelogram arm onthe one hand in the transport position, resting on the support surfaceof the reflector-like projector and, on the other hand, in the positionfor use, a distance away from the support surface. In the region of theconnection of the two parallelogram arms, a gear mechanism imposes asimultaneous movement of the parallelogram arms. Because of thearrangement and owing to the identical length of the two parallelogramarms, the projection means moves along a normal to the support surface.

Overhead projectors and devices for optically capturing objects, whosedeflection mirror means and whose capturing means, respectively, arealso held by means of such a double parallelogram arm relative to thesupport surface in a transport position and a position for use,optionally also in further positions, are also known.

It is therefore the object of the invention to eliminate deficiencies ofthe prior art. Especially it is intended to propose an articulated armfor positioning and orienting a capturing means relative to a base, bymeans of which articulated arm the capturing means is oriented, in atleast two different, predetermined positions of the arm, differentlyrelative to the base.

If the orientation required for a means in the position for use differsfrom that in the transport position, a means detachably fastened to thedouble parallelogram arm can be oriented by hand in a manner known perse to meet the respective requirements. The manual orientation on theone hand reduces the convenience of operation and, on the other hand,often necessitates repeated orientation for precise orientation in apredetermined action. This is time-consuming and is often unsatisfactoryin use.

It is therefore the object of the invention to eliminate deficiencies ofthe prior art. Especially it is intended to propose an articulated armfor positioning and orienting a capturing means relative to a base, bymeans of which articulated arm the capturing means is oriented, in atleast two different, predetermined positions of the arm, differentlyrelative to the base.

This object is achieved by an articulated arm in which the top part hasat least one shaft rotatably relative to the top part and coupled to thecapturing means, wherein an operative mechanical connection between theshaft and at least one of the top rods is provided and designed in sucha way that the capturing means is directed to the support surface onchanging over to the position for use, wherein a rotation of the shaftis imposed relative to the top part and the top rod during pivoting ofthe top rod relative to the top part.

Further advantageous or alternative developments and furtherdevelopments of the invention are described below.

When the term rods is used in association with the invention, elongated,substantially rigid elements in the widest sense are to be understood.These rods can be either solid or can have any desired profile. Theprofiles of the rods may be, for example, such that rods alignedparallel to one another and opposite to one another engage one another.

An articulated arm according to the invention has—like a conventionaldouble parallelogram arm—a base part, a top part, an articulated partand two pairs of rods which connect the base part and the head part withthe articulated arm. In contrast to the prior art, an articulated armaccording to the invention furthermore has a shaft which is rotatablymounted on the top part and has an operative mechanical connection to atleast one of the rods pivotably fastened to the top part. This operativeconnection results in a rotation of the shaft relative to the top partwhen the rod pivots.

In the context of the invention, an operative mechanical connection isto be understood as meaning, for example, engaging gear segments, rodmechanisms or couplings via belts or chains.

A further development of the invention envisages the provision of anarticulated arm according to the invention, comprising at least onespringy element, for example a coil spring, leaf spring or torsionspring. The springy element is to be mounted in a manner known per se onthe articulated arm so that pivoting of the rods results in tensioningand relaxing of the springy element. The springy elements counteract theweight of the held capturing means and of the articulated arm in amanner known per se.

However, it is also possible to provide spring forces exceeding theweights, in order to ensure that the articulated arm automaticallyassumes the extended position. According to the invention, a lockingelement holding the articulated arm in the folded position would have tobe provided in this case.

Furthermore, at least one, especially a mechanical, braking elementwhich resists pivoting of the rod by means of braking forces can also bemounted on the articulated arm. In interplay with a suitable choice ofthe springy element, it is thus possible to provide articulated armsaccording to the invention which hold capturing means in space not onlyin the folded or extended position but also in any desired intermediatepositions. For example, a capturing means can be held in a stable mannerthereby a short distance away from the surface on which the device isplaced. This is advantageous especially for objects also placed next tothe device on the surface. Thus, lateral images of captured objects, forexample, architectural models, small machines, aquaria, chemicalexperimental setups, etc. require capturing means oriented andpositioned in this manner.

The invention is explained in more detail below, purely by way ofexample, with reference to the figures in the drawings.

FIG. 1 shows a device for optically capturing objects in the transportposition, which is provided with an embodiment of an articulated armaccording to the invention, as a side view,

FIG. 2 shows a partial view of the device from FIG. 1 in the positionfor use with extended articulated arm, as a side view, and

FIG. 3 shows the device from FIG. 1 in the position for use with partlyfolded articulated arm, as an oblique view.

FIG. 1 shows a device for optically capturing objects in the transportposition with an articulated arm 1 according to the invention, as a sideview. Here, the articulated arm 1 assumes the folded position. Inaddition to the articulated arm 1, the device has an optically capturingmeans 2 and a lighting means 16.

The articulated arm 1 shown in section is in the form of a doubleparallelogram arm in a manner known per se and has a base part 4, a toppart 7, an articulated part 10, two rods 5, 6 connected to the base andtwo rods 8, 9 connected to the top. The base and top rods 5, 6 and 8, 9,respectively, which are in the form of U-profiles here, are eachprovided with a hole on both sides at their ends. At one end, the baseand top rods 5, 6 and 8, 9, respectively, are pivotably fastened to thebase part 4 and to the top part 7, respectively, by means of thefastening bolts which are inserted into the holes. At the other end, thebase and top rods 5, 6 and 8, 9, respectively, are likewise pivotablyfastened by means of bolts to the articulated part 10, oriented parallelto one another.

Here, the base part 4 is formed as an integral part of a base housing19. That side of the base housing 19 which faces the articulated arm 1is provided with a support surface 3 on which an object to be recordedby the optically capturing means 2 can be placed. It would of coursealso be possible for the base part and base housing to comprise amultiplicity of parts and to be connected to one another, or to providea third part with the support surface and to assign this to the basehousing.

In addition to the fastening bolts for the pivotable fastening of thebase and top rods 5, 6 and 8, 9, respectively, the articulated part 10has two further bolts for mounting two gear wheels 20. These each engagea gear segment 21 which is located on the joint and which in each caseis arranged on the joint end of the base rod 5 or of the top rod 9 andthus form an operative mechanical connection. This imposes, in a mannerknown per se, the simultaneous pivoting of the base and top rods 5, 6and 8, 9. Here, the articulated part 10 is moreover provided with a grippiece 15 on which it is possible manually to exert forces by means ofwhich the articulated arm 1 is brought from one position into anotherposition.

According to the invention, the top part 7 has a shaft 11 which has anoperative mechanical connection to one of the top rods 8, 9. Here, theoperative connection is formed by a first gear segment 12 which isarranged coaxially on the shaft 11 and engages a second gear segment 13.The latter is arranged on the top end of the top rod 9. In principle, itwould also be possible for a third gear segment to be arranged at thetop end of the other top rod 8 and likewise to engage the first gearsegment 12. If the articulated arm 1 is now brought from the foldedposition into another position, the top rod 9 provided with the secondgear segment 13 is pivoted relative to the top part 7. By means of theengaging gears of the first and of the second gear segments 12 and 13,according to the invention the shaft 11—and thus also the capturingmeans 2 coupled to the shaft 11—is rotated relative to the top part 7.In the case of this type of operative connection, the extent of rotationof the shaft 11 can be determined in a manner known per se as a functionof the extent of pivoting of the top rods 8, 9 by an appropriateformation of the two gear segments 12, 13.

In this embodiment, the optically capturing means 2 of the device islocked on the shaft 11 by means of a locking element not shown in FIG.1—as described in more detail below. The capturing means 2 for opticallycapturing objects is provided here with a digital camera whose objectiveis shown schematically by an objective lens 17 and which has an opticalaxis 18. The images of the captured objects are converted intoelectrical signals by means of the digital camera.

In the transport position, the optionally elongated capturing means 2 isheld horizontally over its length on the support surface 3 by means ofthe articulated arm 1. The optical axis 18 is aligned parallel to thesupport surface 3. Furthermore, the lighting means 16 is heldhorizontally on the base part 4 and aligned parallel with the supportsurface 3 by means of the articulated arm 1. The lighting means 16 islikewise locked directly to the top part 7.

Owing to the different lengths of the base rods and of the top rods 5, 6and 8, 9, respectively, neither the capturing means 2 nor the lightingmeans 16 or the articulated arm 1 extends beyond the edge of the basehousing 19. In combination with the orientation of the capturing means 2and of the lighting means 16, the device has extremely compactdimensions in the transport position—as shown in FIG. 1.

FIG. 2 shows a partial view of the device for optically capturingobjects from FIG. 1, comprising the capturing means 2, the lightingmeans 16 and a part of the articulated arm 1. In contrast to FIG. 1, thedevice is shown here in the position for use. The articulated arm 1assumes the preferably extended position. However, the device can alsoassume a position for use in an intermediate position between the foldedposition and the extended position—as shown in FIG. 3.

When the device changes over from the transport position shown in FIG. 1to the position for use shown in FIG. 2, in this embodiment the top rod9 is pivoted 90° clockwise relative to the top part 7. Since theengaging gear segments 12 and 13 have the same radius, the shaft 11 islikewise rotated 90° counterclockwise relative to the top part 7. Thecapturing means 2 locked on the shaft 11 is thus also rotated 90°counterclockwise. The optical axis 18 is now oriented at right angles tothe support surface 3 not shown in FIG. 2, and especially substantiallytowards the centre thereof. The capturing means 2 is thus suitablyoriented for optically capturing an object placed on the support surface3.

In this embodiment, the capturing means 2 is oriented differentlyaccording to the invention depending on position—on the one handaccording to the requirements of the transport position which is shownin FIG. 1 and, on the other hand, according to the requirements of theposition for use of the device which are shown in FIG. 2—by the shaft 11and the operative mechanical connection between the shaft 11 and the toprod 9, which connection is realized by means of the gear segments 12 and13.

In contrast, the lighting means 16 is locked not on the shaft 11 but onthe top part 7, for example by means of a clip which grips around thetop part 7 and is provided with a locking element. Thus, the orientationof the lighting means 16 remains unchanged, in a manner known per se,relative to the base part 4, not shown in FIG. 2, on changing over fromthe transport position to the position for use. If additional lightingis required for capturing an object placed on the support surface, thelighting means 16 is already suitably oriented for this purpose.

FIG. 3 shows the device from FIG. 1 as an oblique view. In contrast toFIG. 1, the device is shown here in a position for use, in which thearticulated arm assumes an intermediate position between the foldedposition and the extended position. The articulated arm can hold thecapturing means 2 at different distances from a surface 22 on which thedevice is placed, by means of springy or braking elements not shown inFIG. 3. In that position of the device which is shown in FIG. 3, imagesof optically captured objects could be made, for example, of anarchitectural model which is not shown in FIG. 3 and is mounted in frontof the objective lens 17 on the surface 22. Owing to the specialrequirements of such an application, it may be necessary here to alignthe optical axis 18 parallel to the support 22. Furthermore, thelighting means 16 should no longer be directed towards the supportsurface 3 but towards the object to be recorded. By exertingpredetermined forces, indicated by two arrows by way of illustration inFIG. 3, on the capturing means 2 and the lighting means 16, these can bereleased from the respective locking and can be oriented in accordancewith the specific requirements.

It would also be possible to provide further locking positions. Onefurther locking position which, when the articulated arm is in theextended state, orients the capturing means 2 exactly with a back-litslide area not shown in FIG. 3 would be helpful, for example, in thecase of relatively frequent capturing slides.

Such a slide area is described in the German Patent Application No. DE102 10 322.4 filed by the same Applicant, with the title “Auflageflächeeines Geräts zur optischen Aufnahme von Objekten [Support surface of adevice for optically capturing objects]”. The corresponding U.S. PatentApplication was published May 19, 2005, as Publication No. U.S.2005/0105181A1.

1. An articulated arm for positioning and orienting a capturing meansfor optically capturing an object relative to a support surface providedfor the object at least in a transport position and a position for use,the articulated arm comprising: a base part on which two parallel baserods are pivotably fastened at one end, a top part on which two paralleltop rods are pivotably fastened at one end, and an articulated part towhich the two base rods and the two top rods are pivotably connected atthe other end, wherein the top part has at least one shaft pivotablyfastened at and rotatable relative to said top part and coupled to thecapturing means, and wherein an operative mechanical connection isprovided between the shaft and at least one of the two top rods, theoperative mechanical connection including a first rotation segmentconnected to the shaft and at least a second rotation segment connectedto one of the two top whereby the capturing means is directed to thesupport surface upon moving into the position for use, wherein rotationand the top rod during pivoting of the top rod, relative to the toppart.
 2. An articulated arm according to claim 1, wherein the operativemechanical connection is effected by engaging gear segments, of which afirst gear segment is connected to the shaft and an at least a secondgear segment is connected to one of the top rods.
 3. An articulated armaccording to claim 1, wherein the articulated arm has at least onespringy element, mounted between the base rods or the top rods, saidspringy element being tensioned or relaxed on pivoting of the rods. 4.An articulated arm according to claim 1, wherein the base part is firmlyconnected indirectly or directly to the support surface, and the shaftis detachably locked to the optically capturing means.
 5. An articulatedarm according to claim 4, wherein on changing over from the transportposition to the position for use of the articulated arm, the shaft isrotated 90° relative to the top part.
 6. An articulated arm according toclaim 4, wherein a lighting device is detachably fastened to the toppart.
 7. An articulated arm for positioning and orienting a capturingmeans for optically capturing an object relative to a support surfaceprovided for the object at least in a transport position and a positionfor use, the articulated arm comprising: a base part on which twoparallel base rods are pivotably fastened at one end, a top part onwhich two parallel top rods are pivotably fastened at one end, and anarticulated part to which the two base rods and the two top rods arepivotably connected at the other end, wherein the top part has at leastone shaft pivotably fastened at and rotatable relative to said top partand coupled to the capturing means, wherein an operative mechanicalconnection between the shaft and at least one of the two top rods isprovided and designed whereby the capturing means is directed to thesupport surface upon moving into the position for use, wherein rotationduring pivoting of the top rod, relative to the top part, and wherein atleast one of the two base rods and at least one of the two top rods havean operative mechanical connection which, on movement of the at leastone base rod relative to the articulated part, imposes a movement of theat least one top rod relative to said articulated part.
 8. Anarticulated arm according to claim 7, wherein the articulated arm has atleast one braking element that is mounted between the base rods and thebase part and that resists pivoting of the rods by frictional forces. 9.An articulated arm according to claim 7, wherein the articulated arm isprovided with a catch that locks the articulated arm in a predeterminedposition.
 10. An articulated arm according to claim 7, wherein thearticulated part is provided with a grip piece.
 11. An articulated armaccording to claim 7, wherein the base part is firmly connectedindirectly or directly to the support surface, and the shaft isdetachably locked to the optically capturing means.
 12. An articulatedarm according to claim 11, wherein upon converting from the transportposition to the position for use of the articulated arm, the shaft isrotated 90° relative to the top part.
 13. An articulated arm accordingto claim 11, wherein a lighting device is detachably fastened to the toppart.
 14. A device for optically capturing objects, comprising: asupport surface on which an object can be placed, capturing means forcapturing the object placed on the support surface, and an articulatedarm that positions and orients the capturing means for opticallycapturing the object relative to the support surface provided for theobject at least in a transport position and a position for use, saidarticulated arm comprising: a base part on which two parallel base rodsare pivotably fastened at one end, a top part on which two parallel toprods are pivotably fastened at one end, and an articulated part to whichthe two base rods and the two top rods are pivotably connected at theother end, wherein the top part has at least one shaft pivotablyfastened at and rotatable relative to said top part and coupled to thecapturing means, and wherein an operative mechanical connection isprovided between the shaft and at least one of the two top rods, theoperative mechanical connection including a first rotation segmentconnected to the shaft and at least a second rotation segment connectedto one of the two top whereby the capturing means is directed to thesupport surface upon moving into the position for use, wherein rotationand the top rod during pivoting of the top rod, relative to the toppart.
 15. A device according to claim 14, wherein the operativemechanical connection is effected by engaging gear segments, of which afirst gear segment is connected to the shaft and an at least a secondgear segment is connected to one of the top rods.
 16. A device accordingto claim 14, wherein the articulated arm has at least one springyelement mounted between the base rods or the top rods, said springyelement being tensioned or relaxed on pivoting of the rods.
 17. A deviceaccording to claim 14, wherein the base part is firmly connectedindirectly or directly to the support surface, and the shaft isdetachably locked to the optically capturing means.
 18. A deviceaccording to claim 17, wherein on changing over from the transportposition to the position for use of the articulated arm, the shaft isrotated 90° relative to the top part.
 19. A device according to claim17, wherein the capturing means is provided with a digital camera forconverting images of the captured objects to electrical signals.
 20. Adevice for optically capturing objects, comprising: a support surface onwhich an object can be placed, capturing means for capturing the objectplaced on the support surface, and an articulated arm that positions andorients the capturing means for optically capturing the object relativeto the support surface provided for the object at least in a transportposition and a position for use said articulated arm comprising: a basepart on which two parallel base rods are pivotably fastened at one end,a top part on which two parallel top rods are pivotably fastened at oneend, and an articulated part to which the two base rods and the two toprods are pivotably connected at the other end, wherein the top part hasat least one shaft pivotably fastened at and rotatable relative to saidtop part and coupled to the capturing means, wherein an operativemechanical connection between the shaft and at least one of the two toprods is provided and designed whereby the capturing means is directed tothe support surface upon moving into the position for use, whereinrotation during pivoting of the top rod, relative to the top part, andwherein at least one of the two base rods and at least one of the twotop rods have an operative mechanical connection which, on movement ofthe at least one base rod relative to the articulated part, imposes amovement of the at least one top rod relative to said articulated part.21. A device according to claim 20, wherein the articulated arm has atleast one braking element that is mounted between the base rods and thebase part and that resists pivoting of the rods by frictional forces.22. A device according to claim 20, wherein the articulated arm isprovided with a catch that locks the articulated arm in a predeterminedposition.
 23. A device according to claim 20, wherein the articulatedpart is provided with a grip piece.
 24. A device according to claim 20,wherein the base part is firmly connected indirectly or directly to thesupport surface, and the shaft is detachably locked to the opticallycapturing means.
 25. A device according to claim 24, wherein uponconverting from the transport position to the position for use of thearticulated arm, the shaft is rotated 90° relative to the top part. 26.A device according to claim 24, wherein the capturing means is providedwith a digital camera for converting images of the captured objects toelectrical signals.